[antlr-interest] Gramar without semicolon

[Joan Pujol]

Hi,

I've to write a compiler for a pseudocode language to
use in a elearning platform.
The pseudocode language, at first, don't use semicolon
to end instructions(it's only used as a separator to
use multiple instructions in a single line). And I
have some problems with the gramar.

I make a simple case with only two instructions an if
and an assignament:

instructions: (instruction)+;
instruction: inst_if | inst_assig;
inst_if: IF expr THEN (NL)* instructions (ELSE (NL)*
instructions)? ENDIF ((NL)+ |SEMICOLON instruction);
inst_assig: IDENT ASSIG expr ((NL)+ |SEMICOLON
instruction);

This I think that works quite well and recognizes
thinks like

IF expr THEN inst1;inst2
ELSE  inst1
END IF

But it can't recognize
IF expr THEN inst1 ELSE inst2 END IF

And I don't know how to manage this, I think that I've
to use semantic predicates but I am a little confused.

Somebody knows how to manage this, or has implemented
a similar grammar (without semicolon and similar to
Visual Basic)

Cheers,

=====
---
Joan Jesús Pujol Espinar


	
	
		
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